Aircraft, when at a terminal or otherwise on the ground, require utility support of various types especially when the aircraft engines are not powered up. One utility need is electrical power in the form of alternating current (AC) power at various frequencies and voltages and/or direct current (DC) power at various voltages. The required voltages and other parameters of the electrical power differ from aircraft to aircraft.
Aircraft on the ground may also require bleed air. Bleed air is high pressure air used by aircraft to operate onboard environmental control systems and to start gas turbine engines. When in flight, bleed air is siphoned off of the compressor stage of the aircraft engine, but this source of bleed air is not available when the aircraft is on the ground and de-powered.
A third utility need for aircraft on the ground is conditioned air, including for the cockpit and the cabin, as well as to provide cooling or heating to onboard electrical systems.
To date, the foregoing three utility functions have been fulfilled by individual pieces of ground supported equipment (GSE). In this regard, individual utility carts, for ground power, are commercially available. Such utility carts are typically powered by an internal combustion engine. The engine is paired with an electrical generator. The power from the generator must be converted to the correct type of power (AC/DC) at the correct power parameters through the use of a converter system. Typically, such power generators are relatively large and thus are mounted on a cart as a singular or separate equipment unit.
Bleed air has also typically been provided using a singular utility cart on which is mounted an internal combustion engine and a large screw-type compressor in order to provide air at a sufficient pressure and volume to meet aircraft needs, including for starting the aircraft engines. For example, bleed air is supplied at 150 pounds of air per minute at 65 psia.
Air conditioning units also typically have been mounted on individual carts. The units are powered by an internal combustion engine paired with a refrigerant-based air conditioning system. The components required for a refrigerant-based system are numerous, thereby occupying large volumes and thus commonly requiring a separate cart. Air cycle air conditioning systems have also been developed wherein pressurized air is supplied to the air cycle machine for further compression and then rapid cooling by expansion before being supplied to the aircraft. In these situations, the compressed air supplied to the air cycle machine originates from an external compressed air source, typically a large central compressor plant located at the airport.
There has been some attempt to seek to combine utility supply for aircraft, including for example providing both power and conditioned air to an aircraft. Such units utilize a diesel driven or electric motor driven power plant mounted on a cart to power both an air conditioning system and an electrical generator. However, such systems do not also provide bleed air for aircraft.
The present disclosure seeks to provide an integrated, singular modular cart that provides three utility needs for aircraft including electrical power, air conditioning, and bleed air thereby eliminating the requirement for multiple ground support carts by replacing heretofore three individual ground support carts with a singular unit.